ST. PETERSBURG — Amid much fanfare two years ago, developer Darryl LeClair unveiled bold plans for a new Tampa Bay Rays stadium at Carillon Business Park in the Gateway area.

It offered a St. Petersburg solution to the team's pleas for a new stadium, and it was about 15 minutes closer to Tampa than Tropicana Field.

But no one from the Rays ever approached LeClair, who is close to giving up on his dream of building a mixed-use stadium, office and residential project on 16 acres he owns south of Ulmerton Road.

"We'd like to keep the window open, but we can't afford to keep it open much longer," LeClair told the Times. "We tried to help facilitate the baseball discussion and it played out the way it played out. We can't sit around and wait for baseball to make a decision. We're moving forward."

The city's Community Planning and Preservation Commission quietly approved last week a preliminary zoning change that would allow LeClair to more intensely develop the site. He wasn't at the meeting, and baseball was never mentioned.

In an interview later, LeClair said he plans to start construction next summer on "Echelon City Center," a mixed-use project that will combine office, retail and residential properties, as well as a hotel.

The first phase would be an apartment building. At that point, he said the Rays could still jump on board. Any stadium would share exterior walls with retail, apartments and the hotel.

But when he adds other buildings onto the stadium footprint — probably by the end of 2016 — a ballpark will no longer fit, LeClair said.

Rays officials have said Tropicana Field cannot sustain baseball in the long run. They want to explore possible new sites on both sides of the bay.

St. Petersburg officials, who hold a contract that binds the team to the Trop through 2027, have refused so far to allow them to look outside Pinellas County.

Rays owner Stuart Sternberg has maintained that any new stadium location must be "pitch perfect.'' He has refused to negotiate on any single site until he can explore all possibilities throughout Tampa Bay.

He might get that chance. Team officials have held several discussions recently with new Mayor Rick Kriseman, and both sides describe the talks as cordial and fruitful.

For Carillon to remain in the stadium hunt, LeClair said, the Rays would have to start their regionwide search soon and keep it short — say, six months. The Rays have said they need time to conduct traffic and demographic studies on various sites, and also gauge corporate support.

"Carillon's redevelopment news has had no impact on the good conversations that the mayor continues to have with Rays leadership," said Ben Kirby, the mayor's spokesman.

The Rays weren't aware of the potential zoning change but aren't looking at sites, said Melanie Lenz, the team's vice president of development and business affairs. "We do look forward for the ability to be able to look," she said.

LeClair described his City Center plan as a place where Carillon's 14,000 office workers could walk to lunch, shop and, for some, sleep. Demand for apartments in the area has outpaced supply, he said, and leisure opportunities are limited.

"What we haven't done is provided the amenities for folks to have a place to eat, to hang out, to pick up a bottle of wine, not have to fight the traffic to Tampa," LeClair said.

Council member Jim Kennedy said he was frustrated but not surprised by the dimming prospects for a new ballpark in his district.

"You can only keep an offer on the table for so long," Kennedy said. "The fact that the Rays refuse to even consider it, critique it or take it as a learning experience . . . to me, that kind of evidences difficulty to have constructive communication."

Like most potential stadium sites, Carillon has substantial drawbacks. Traffic going in and out already backs up during rush hour. Parking during day games would be a nightmare. Heavy rains can flood streets. And major Carillon corporations, such as Raymond James Financial, have not signaled support for a neighborhood stadium.

Still, a civic group called the ABC Coalition, which evaluated stadium locations in 2010, labeled the Pinellas Gateway area as one of three good possibilities, along with Hillsborough County's West Shore district and downtown Tampa. Though Gateway locations included the old Toytown landfill, vacant land north of Gandy Boulevard and the Derby Lane site, Carillon was the centerpiece.

If the Greenlight Pinellas mass transit initiative passes in November, Carillon will gain a light rail station, which theoretically could be incorporated into a ballpark.

Besides LeClair's holdings, two other Carillon parcels are large enough to hold a stadium, but neither fronts Ulmerton Road's commercial ambience and those owners have not expressed any interest in baseball.